The present invention relates to a cage for roller bearings and specifically to an improved plastic cage for cylindrical roller bearings. The cage consists of a pair of spaced annular side bars and a plurality of crosspieces which join the side bars to form pockets for holding the rolling elements. The rolling elements are guided by elastically deformable retaining projections in the pockets in a manner to prevent them from falling out and thus the cage and the rolling elements form an integral unitary assembly.
Cages of this general type are not new per se. For example, West German Registered Design No. 7,625,839 shows a cage produced by casting or injection molding. However, this cage requires a large amount of material, especially in the large sizes and consequently they cool relatively slowly in the mold so that the production quantities per unit time are relatively low. It has also been found that the dimensional accuracy of these prior cages is not satisfactory.